• Journal of Microbiology and Biotechnology
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• 제1권1호
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• pp.79-83
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• 1991

The effects of phosphate concentration in the medium, feeding of biosynthetic precursor, and the addition of exogenous berberine on cell growth and berberine production were studied in cell suspension cultures of Thalictrum rugosum. The depletion of phosphate in the medium enhanced the specific productivity up to twofold with significant release of berberine into the medium. Extracellular berberine was 19% of the total in the culture without phosphate while it was 2-5% of total berberine in the culture with even low amounts of phosphate. Precursor feeding was not effective in enhancing alkaloid formation. Initial presence of exogenous berberine did not have much effect on cell growth and alkaloid production. It was found that the cells have the capacity to take up large quantities of berberine. When $500{\;}mg{\cdot}l^{-1}$ of berberine was added exogenously at the beginning, 81% of total berberine was found in the cells.

• KSBB Journal
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• 제8권5호
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• pp.488-494
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• 1993

본 연구에서는 캘리포니아 양귀비(Eschscholtzia californica) 현탁배양세포의 주요 이차대사산물인 benzophenanthridine alkaloid의 생성을 증가시키기 위해 생합성 전구체인 tyrosine, tyramine, dopamine 그리고 L-dopa를 exponential phase 말기에 투여하였다. 그리고 이때 yeast elicitor와 전구체를 동시에 투여한 것과 비교하여 보았다. 그 결과 적당량의 전구체 투여시 benzophenanthridine alkaloid의 생성은 대조구(무처리)에 비해 증가하였다. 그리고 elicitor와 전구체를 동시에 투여해 주었을 때 대조구(elicitor만 처리)에 비해 상당히 증가하였는데, 이것은 elicitor에 의해 유도된 이차대사 관련 효소에 의해 전구체의 biotransformation이 촉진된 것이라 생각된다. 이와 같이 전구체 투여에 의해 이차대사산물의 생성을 증가시키려 할 때 전구체만 투여하는 것보다는 촉진제를 동시에 투여함으로써 최종산물의 생성을 극대화시킬 수 있으리라 생각되며, 식물세포배양의 산업화에 유용하게 이용되리라 생각된다.

• 한국해양생명과학회지
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• 제7권1호
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• pp.1-9
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• 2022

This investigation aimed to assess the appetite response changes of olive flounder to starving and re-feeding conditions. Three different feeding groups (2 weeks feeding, fed; 2 weeks starving, starved; and 1 week starving and 1 week feeding, re-fed) were established to examine the changes in appetite-related genes for each group. The weight gain of the fish was highest for the fed group and lowest for the starving group. Based on the daily feed intake (DFI) and cumulative feed intake (CFI), overall food intake was found to increase in the re-fed group more than in the fed group from week 1 to week 2 of the experiment. Hypocretin neuropeptide precursor (HCRT) and galanin receptor 1 (GAL-R1) mRNA expression in the brain of olive flounder were decreased in the starved group. Corticotropin-releasing hormone (CRH) was decreased in all experimental groups, except for the fed group. However, overall leptin concentrations in the plasma did not change across groups. Considering the differences between this study and previous studies on starving and feeding, various factors (except the production and expression mechanisms of appetite-related factors in response to starving) are likely acting on the appetite responses of the fish. In this study, a 1-week re-feeding period induced substantial effects on appetite response when compared to a 2-week feeding period. These findings show that even if re-feeding is performed after starving, the unbalance caused by the re-feeding can affect various physiological changes in fish by feed intake efficiency.

• 한국약용작물학회지
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• 제13권2호
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• pp.91-94
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• 2005

Plants have been known to accumulate a very diverse range of triterpene saponins. We have investigated the regulation of saponin biosynthesis in higher plants using Centella asiatica (L.) Urban as a model plant. Effects of a feeding precursor on asiaticoside production from leaves and on the level of two-type OSCs mRNA were investigated. As a feeding precursor, squalene negatively affected the levels of CYS and bAS mRNA, but it also decreased the production of asiaticoside from whole plants. Plant hormones regulate secondary metabolism, and in plant tissue cultures they could affect both culture growth and secondary metabolite production. Although enhancement of asiaticoside production from whole plant cultures by addition of TDZ (thidiazuron) has been reported, the positive effect of TDZ on the levels of OSCs transcripts was not observed.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.381.2-381.2
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• 2014

In this study the amorphous carbon films were deposited by PECVD at the substrate temperature range of 250 to $600^{\circ}C$, and the process conditions of higher and lower precursor flow rate, respectively. The temperature was a main parameter to control the density and mirco-structures of carbon films, and their's properties depended with the process temperatrue are changed by controlling precursor flow rate. The precursor feeding rate affect on the plasma ion density and a deposition reactivity. This change of film properties was obtained the instrinsic stress, FT-IR & Raman analysis, refractive index (RI) and ext. coef. (k) measured by ellipsometer. In the process conditions of lower and higher flow rate of precursor it had a different intrinsic stress as a function of the substrate temperature.

• 한국재료학회지
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• 제22권10호
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• pp.531-538
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• 2012

Hollow silica spheres were prepared by spray drying of precursor solution of colloidal silica. The precursor solution is composed of 10-20 nm colloidal silica dispersed in a water or ethanol-water mixture solvent with additives of tris hydroxymethyl aminomethane. The effect of pH and concentrations of the precursor and additives on the formation of hollow sphere particles was studied. The spray drying process parameters of the precursor feeding rate, inlet temperature, and gas flow rate are controlled to produce the hollow spherical silica. The mixed solvent of ethanol and water was preferred because it improved the hollowness of the spheres better than plain water did. It was possible to obtain hollow silica from high concentration of 14.3 wt% silica precursor with pH 3. The thermal conductivity and total solar reflectivity of the hollow silica sample was measured and compared with those values of other commercial insulating fillers of glass beads and $TiO_2$ for applications of insulating paint, in which the glass beads are representative of the low thermal conductive fillers and the $TiO_2$ is representative of infrared reflective fillers. The thermal conductivity of hollow silica was comparable to that of the glass beads and the total solar reflectivity was higher than that of $TiO_2$.

• 한국세라믹학회지
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• 제36권1호
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• pp.55-60
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• 1999

Hexamethyldisilane(Si2(CH3)6)의 single precursor를 출발원료로 사용하여 화학기상증착법으로 Si 기판위에 buffer층의 형성 없이 $\beta$-SiC의 박막을 증착하였다. Si 기판과 SiO2 mask에서 SiC 박막 증착의 선택성을 위하여 HCI의 식각 가스를 도입하였고 출발원료와 HCI 가스의 공급방법을 변화시켰다. SiC 박막 증착 과정에서 HCI 가스의 도입이 막의 표면 조도에 미치는 영향을 조사하였고 Hall 측정을 통하여 SiC 막의 전기적 특성을 조사하였다.

• 한국약용작물학회지
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• 제16권4호
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• pp.268-272
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• 2008

참돌꽃 캘러스로부터 elicitor와 전구체가 salidroside 생산에 미치는 영향을 조사하였다. Elicitor로서 효모추출물, 연자성 세라믹, methyl jasmonate, jasmonic acid, ascorbic acid, 및 중금속 ($CuCl_2$/$CdCl_2$)을 캘러스 배양에 처리하였다. 효모추출물 $0.2g/\ell$농도로 처리한 결과 처리하지 않은 대조구에 보다 3.45배 증가시켰다. 사용된 elicitor 중 효모추출물이 가장 높은 salidroside 생산을 보여 가장 적합한 elicitor로 사료된다. 전구체로서 L-phenylalanine과 L-tyrosine을 배지에 첨가하여 4일 간 배양 처리하였다. Salidroside 함량분석 결과 캘러스로부터 전구체들은 유용물질 생합성에 영향을 주지는 않았다. 캘러스 배양에 첨가 처리된 L-tyrosine의 모든 농도의 경우에는 캘러스 생장뿐만 아니라 salidroside 생산을 감소시켰다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권1호
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• pp.36-38
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• 2003

The effect of different feeding ratios of concentrate to roughage on ruminal lipid synthesis in vitro was examined. Three sheep fitted with a rumen fistula were fed three different ratios (8:2, 4:6 and 0:10) of concentrate and roughage, and their rumen liquor were used for incubation. $^{13}C$-labeled glucose or sodium acetate as substrate was added to cultures of rumen liquor, and they were incubated for 6 h. The total lipid in the culture of the rumen liquor was extracted, and the percentage of $^{13}C$ excess was analyzed. The percentage of $^{13}C$ excess recovered when incubated with glucose increased with increased ratio of concentrate in the diet. The values of cultures incubated with glucose were higher than those incubated with sodium acetate except the roughage-only feeding. In the roughage-only diet, the percentage of $^{13}C$ excess when incubated with sodium acetate was highest of all diets. The recovery percentage of $^{13}C$ from glucose increased with increased ratio of concentrate. The recovery percentage of $^{13}C$ from sodium acetate addition in only roughage feeding was highest among the three diets. The recovery percentage of $^{13}C$ from glucose was markedly higher than that of sodium acetate addition in all feedings. The results indicate that high concentrate feeding facilitates lipid synthesis by rumen microorganisms, and that glucose may be the precursor for lipid synthesis rather than acetic acid.

• KSBB Journal
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• 제13권2호
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• pp.174-180
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• 1998

유럽주목(Taxus baccata Pendula)현탁 세포 배양에서(10-deacetyl) baccatin III 생산을 증진시키는 연구를 하였다. 높은 초기 당 농도가(10-deacetyl) baccain III 생산을 증진시키는 연구를 하였다. 6% 의 초기 포도당과 자당의 경우 1O-deacetyl baccatin III 생산을 각각 3.배와 2.5배씩 증가시켰다. Baccain III도 초기 포도당 8%에서,초기 자당 6%에서 최대값을 보였다. 일리시터로서 methyl jasmonate는(10-deacetyl) baccatin III 의 생성은 $50{\mu}$M에서 최대치를 보였는데 이는 대조구에 비하여 4.5배 증가한 값이었다.Baccatin III 의 경우 methyl jasmonate $100{\mu}$M에서 생성된 Baccatin III 최대치는 대조구에 비하여 7.배 증가한 값이었다. Methyl jasmonate elicitation 에 의한(1O-deacetyl) baccatin III.과 각 taxane의 시간별 생성 경향을 보면 baccatin III와 10-deacetyl baccatin III는 투여 후 1일 까지 생성이 증가하다 그 후부터 감소하였고, paclitaxel, 10-deacetyl taxol 및 cephalomanine 의 생성이 이어졌다. (10-deacetyI) baccatin III의 생합성을 증가시키기 위하여 전구 물질을 투여하였다. Benzoic acid를 $500{\mu}M$로 투여 하였을 때 10-deacetyl baccatin III 및 baccatin III의 생산은 대조구의 비하여 각각 10배와 13배 증가 하였다. Lysine도 $500{\mu}M$로 투여하였을 때 baccatin III 의 생성량을 대조구 보다 8배 증가시켰다. 증가시켰다.